let obj = {
  a: 0,
  b: 1
}
this.obj = obj
console.log(1);
function fn() {
  console.log(this.a)
  console.log(this.b)
}
let newFn = fn.bind(obj)
let arrowFn = () => {
  console.log(this.obj.a)
  console.log(this.obj.b)
}
console.log('open~')
newFn()
arrowFn()